The present invention relates to a copier selectively operable in a cover plate mode which uses a cover plate and an automatic document feeder (ADF) mode which uses an ADF and, more particularly, to a copier provided with an implementation for preventing an original document left unremoved on a glass platen after an ADF mode operation from being not driven out of the copier to jam the copier and thereby being damaged itself.
A copier is generally operated in one of two different modes: a cover plate mode which uses a cover plate and an ADF mode which uses an ADF, as stated above. Specifically, in the cover plate mode an original document is laid on a glass platen of a copier body and then pressed from above by a cover plate which is openably mounted on the copier body. In the ADF mode which may be selected when a number of original documents are to be reproduced continuously, documents are loaded on a document feed table and then fed one by one by the ADF automatically to between the cover plate and the glass platen, each document undergoing reproduction being driven out of the copier body automatically. These two modes available with a copier promote efficient copying operations.
In the cover plate mode, it often occurs that a document is inadvertently left on the glass platen after it has been copied. When the ADF mode operation is effected without removing such a document, the document is not discharged from the copier to jam the copier and is therefore damaged itself. This kind of trouble has heretofore been coped with by adopting an audible alarm such as a buzzer or voice or a visible alarm such as a display which is provided on an operation board.
A problem with the buzzer or similar audible alarm is that it usually produces low sound for only a short period of time to avoid annoyance and, therefore, a person is apt to start on the next operation without noticing the sound. Even the display on the operation board is often overlooked by another person who may intend to operate the copier in the ADF mode. In any case, the document left on the glass platen would jam the copier without being discharged from the copier body.